Makch 23, 1906.] 



SCIENCE. 



459 



seconds of totality. Some of these show 

 the coronal streamers to exceptional length. 



5. Sketches of the corona with usual re- 

 sults. 



6. Observations of shadow bands begun 

 at least ten minutes prior to totality : bands 

 wavering and narrow, moving swifter than 

 one could walk, at right angles to the wind, 

 their length with it, and waxing and 

 waning five times during the interval of 

 observation preceding totality. These 

 observations communicated in detail to 

 Mr. Lawrence Rotch of the Blue Hill Ob- 

 servatory. Other results in the Astrophys- 

 ical Journal. 



The Philadelphia Observatory : Monroe B. 



Snyder. 



The Philadelphia Observatory, an out- 

 growth of the old Central High School Ob- 

 servatory (1837-1900), was planned by the 

 writer for an astrophysical observatory to 

 begin with the twentieth century. The 

 plan included a city station, chiefly for 

 solar work and necessary popular instruc- 

 tion, and a suburban station, not yet real- 

 ized, where certain lines of celestial pho- 

 tography could be undertaken. Peculiar 

 difficulties delayed completion of the build- 

 ing and equipment, and there was a marked 

 absence of financial and other support for 

 the scientific work, so that not until early 

 in 1905 was the really superb equipment, 

 designed for both stations, received, and, 

 as far as possible, erected at the city sta- 

 tion in the new building of the Philadelphia 

 Central High School. 



On March 9, 1905, a destructive fire 

 (probably originating in a combination gas 

 and electric-light fixture), and long feared 

 by the director of the observatory and 

 others on account of municipal neglect of 

 the usual fire precautions, swept the tower 

 and destroyed an equipment and astro- 

 nomical library valued at approximately 

 $55,000, and produced a loss in equip- 



ment and building of more than $100,000. 

 The equipment destroyed represented in a 

 number of respects the very best attainable 

 in instruments of moderate size, and in- 

 cluded: A fifteen-inch refractor with 

 Warner and Swasey mounting, the finest 

 for its size, and provided with both a visual 

 objective and a photographic objective of 

 excellent definition, by Brashear; a "Wads- 

 worth-Hale spectroheliograph designed to 

 photograph the sun in three different wave- 

 lengths simultaneously; a large Keeler 

 spectroscope and spectrograph, attached to 

 the telescope on the day of the fire for the 

 purpose of rediscovering (during maxi- 

 mum solar activity) Hale'.s disturbance in 

 the sun's spectrum; a Warner and Swasey 

 filar micrometer; a four-inch portable 

 transit instrument with the writer's elec- 

 trical transiter attached; clocks and 

 chronographs (partially destroyed) ; a 

 five-inch Rowland concave grating finely 

 mounted by Brashear; a goodly equipped 

 mechanical shop and photographic labo- 

 ratory; and many smaller but valuable 

 physical appliances. 



The loss of a carefully selected library 

 of some four thousand volumes represent- 

 ing the chief periodicals and literature in 

 astronomy and astrophysics almost com- 

 pleted the destruction of years of effort. 

 An eight-inch refractor and an unmounted 

 set of Brashear eight-inch curved plate 

 star cameras were rescued. 



The main pui-pose, under the conditions 

 of work hitherto allotted, was not only 

 that the equipment should as a whole ex- 

 press the best current science, but that 

 certain instruments like the spectrohelio- 

 graph and its method of operation, the 

 transiter, the new form of Hough printing 

 chronograph, and the large curved plate 

 star cameras should represent distinct ad- 

 vances in observatory equipment. 



The observatory is in process of recon- 

 struction. 



